630 research outputs found
Coral community data Heron Island Great Barrier Reef 1962â2016
Here we describe benthic composition data derived from benthic photoquadrats collected over 41 surveys between 1962 and 2016 at four sites on Heron reef, at the southern end of Australiaâs Great Barrier Reef, to assess change in coral composition over time. Surveys have often been annual, in a few years sub-annual, and the longest gap is six years. A subset of the data from two sites with the most complete records has been fully processed to allow the size of all individual colonies, and changes in species composition and cover, to be tracked over time. The taxonomy in these quadrats has been carefully checked for internal consistency, and is generally at the species level. A second subset has been processed, but has not been through full quality control, while a third subset exists as images only. This is the longest, 56 years, regular photographic record of coral cover in existence, and provides a valuable temporal contrast dating back in time to more recent studies of greater geographic extent and/or resolution.Jason E. Tanner, Joseph H. Connel
Optical signatures of spin-orbit exciton in bandwidth-controlled Sr2IrO4 epitaxial films via high-concentration Ca and Ba doping
We have investigated the electronic and optical properties of (Sr1-xCax)2IrO4 (x=0-0.375) and (Sr1-yBay)2IrO4 (y=0-0.375) epitaxial thin films, in which the bandwidth is systematically tuned via chemical substitutions of Sr ions by Ca and Ba. Transport measurements indicate that the thin-film series exhibits insulating behavior, similar to the Jeff=1/2 spin-orbit Mott insulator Sr2IrO4. As the average A-site ionic radius increases from (Sr1-xCax)2IrO4 to (Sr1-yBay)2IrO4, optical conductivity spectra in the near-infrared region shift to lower energies, which cannot be explained by the simple picture of well-separated Jeff=1/2 and Jeff=3/2 bands. We suggest that the two-peak-like optical conductivity spectra of the layered iridates originates from the overlap between the optically forbidden spin-orbit exciton and the intersite optical transitions within the Jeff=1/2 band. Our experimental results are consistent with this interpretation as implemented by a multiorbital Hubbard model calculation: namely, incorporating a strong Fano-like coupling between the spin-orbit exciton and intersite d-d transitions within the Jeff=1/2 band. ? 2017 American Physical Society.113Ysciescopu
An entomocentric view of the Janzen-Connell hypothesis
In 1987, in the first issue of Conservation Biology, Edward O. Wilson wrote about the âlittle things that run the worldâ â the importance and conservation of insects (Wilson, 1987). Readers of Insect Conservation and Diversity will no doubt be very familiar with the concept. Sadly, however, this perception is not as widely shared among the rest of the scientific community as it should be, and insects are still comparatively neglected as a prime focus of scientific investigations
Dynamics of tree diversity in undisturbed and logged subtropical rainforest in Australia
In subtropical rainforest in eastern Australia, changes in the diversity of trees were compared under natural conditions and eight silvicultural regimes over 35 years. In the treated plots basal area remaining after logging ranged from 12 to 58 m2 per ha. In three control plots richness differed little over this period. In the eight treated plots richness per plot generally declined after intervention and then gradually increased to greater than original diversity. After logging there was a reduction in richness per plot and an increase in species richness per stem in all but the lightest selective treatments. The change in species diversity was related to the intensity of the logging, however the time taken for species richness to return to pre-logging levels was similar in all silvicultural treatments and was not effected by the intensity of treatment. These results suggest that light selective logging in these forests mainly affects dominant species. The return to high diversity after only a short time under all silvicultural regimes suggests that sustainability and the manipulation of species composition for desired management outcomes is possible
Astrophysical Uncertainties in the Cosmic Ray Electron and Positron Spectrum From Annihilating Dark Matter
In recent years, a number of experiments have been conducted with the goal of
studying cosmic rays at GeV to TeV energies. This is a particularly interesting
regime from the perspective of indirect dark matter detection. To draw reliable
conclusions regarding dark matter from cosmic ray measurements, however, it is
important to first understand the propagation of cosmic rays through the
magnetic and radiation fields of the Milky Way. In this paper, we constrain the
characteristics of the cosmic ray propagation model through comparison with
observational inputs, including recent data from the CREAM experiment, and use
these constraints to estimate the corresponding uncertainties in the spectrum
of cosmic ray electrons and positrons from dark matter particles annihilating
in the halo of the Milky Way.Comment: 21 pages, 9 figure
Exact two-particle eigenstates in partially reduced QED
We consider a reformulation of QED in which covariant Green functions are
used to solve for the electromagnetic field in terms of the fermion fields. It
is shown that exact few-fermion eigenstates of the resulting Hamiltonian can be
obtained in the canonical equal-time formalism for the case where there are no
free photons. These eigenstates lead to two- and three-body Dirac-like
equations with electromagnetic interactions. Perturbative and some numerical
solutions of the two-body equations are presented for positronium and
muonium-like systems, for various strengths of the coupling.Comment: 33 pages, LaTex 2.09, 4 figures in EPS forma
Pond canopy cover: a resource gradient for anuran larvae
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72395/1/j.1365-2427.2005.01497.x.pd
âNdiyindodaâ [I am a man]: theorising Xhosa masculinity
Masculinity studies in South Africa depend on Western gender theories to frame research
questions and fieldwork. This article argues that such theories offer a limited understanding of Xhosa constructions of masculinity. Xhosa notions of masculinity are embodied in the concept of indoda, meaning a traditionally circumcised person. This article explores the nuanced meanings of indoda and its relationship to other masculinities, like uncircumcised boys [inkwenkwe] and medically circumcised men. The discussion reveals that indoda is the most âhonouredâ form of masculinity. A traditionally circumcised individual is regarded as indoda, a real man, irrespective of his sexual orientation or class, and this affords him certain rights and privileges. Inkwenkwe and medically circumcised men embody âsubordinateâ forms of masculinity and are victims of stigma and discrimination by indoda. This requires us to revisit some Western theories of masculinity which place heterosexual men at the top of a masculine hierarchy and gay men at the bottom. It furthermore requires us to pay attention to the body when theorising Xhosa masculinity, since it is a principal way of âprovingâ and âdefendingâ Xhosa manhood.IBS
The complications of âhiring a hubbyâ: gender relations and the commoditisation of home maintenance in New Zealand
This paper examines the commoditization of traditionally male domestic tasks through interviews with handymen who own franchises in the company âHire a Hubbyâ in New Zealand and homeowners who have paid for home repair tasks to be done. Discussions of the commoditization of traditionally female tasks in the home have revealed the emotional conflicts of paying others to care as well as the exploitative and degrading conditions that often arise when work takes place behind closed doors. By examining the working conditions and relationships involved when traditionally male tasks are paid for, this paper raises important questions about the valuing of reproductive labour and the production of gendered identities. The paper argues that while working conditions and rates of pay for âhubbiesâ are better than those for people undertaking commoditized forms of traditionally female domestic labour, the negotiation of this work is still complex and implicated in gendered relations and identities. Working on the home was described by interviewees as an expression of care for family and a performance of the ârightâ way to be a âKiwi blokeâ and a father. Paying others to do this labour can imply a failure in a duty of care and in the performance of masculinity
Sporting embodiment: sports studies and the (continuing) promise of phenomenology
Whilst in recent years sports studies have addressed the calls âto bring the body back inâ to theorisations of sport and physical activity, the âpromise of phenomenologyâ remains largely under-realised with regard to sporting embodiment. Relatively few accounts are grounded in the âfleshâ of the lived sporting body, and phenomenology offers a powerful framework for such analysis. A wide-ranging, multi-stranded, and interpretatively contested perspective, phenomenology in general has been taken up and utilised in very different ways within different disciplinary fields. The purpose of this article is to consider some selected phenomenological threads, key qualities of the phenomenological method, and the potential for existentialist phenomenology in particular to contribute fresh perspectives to the sociological study of embodiment in sport and exercise. It offers one way to convey the âessencesâ, corporeal immediacy and textured sensuosity of the lived sporting body. The use of Interpretative Phenomenological Analysis (IPA) is also critically addressed.
Key words: phenomenology; existentialist phenomenology; interpretative phenomenological analysis (IPA); sporting embodiment; the lived-body; Merleau-Pont
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